The young people could not draw clear lines of demarcation between work and play, despite multiple warnings during their working hours.
They couldn't stop chatting with each other, and without having done much work, they went home.
ご質問ありがとうございます。
"The young people could not draw clear lines of demarcation between work and play,"＝「若者たちは仕事と遊びの境界線を明確に付けられなかった、」
"despite multiple warnings during their working hours."＝「仕事中に何度も注意をされたのにも拘わらず。」
"They couldn't stop chatting with each other,"＝「お互いお喋りを止めることが出来ず」
"and without having done much work,"＝「仕事もろくにせず」
"they went home."＝「彼等は帰宅した。」
ご参考に。
"The young people couldn't find the line between work and play and continued to talk amongst themselves."
"The young people couldn't find the line between work and play and continued to talk amongst themselves."
"the young people" 「若者達」
"couldn't find ~”「〜を見付かれません」
"the line"「線」"the boundary" 「境界線」も使えます。
"between ~" 「〜の間」
"work" 「仕事」
"play" 「遊び」
"the line between work and play" 「仕事と遊びの境界線」
"continued to talk amongst themselves" 「喋りを続けた」
"amongst themselves" 「自分で」
アメリカ合衆国 
オーストラリア 
